eness of MSCs. ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.BACKGROUND Critically sized bone defects represent a significant challenge to orthopaedic surgeons worldwide. These defects generally result from severe trauma or resection of a whole large tumour. Autologous bone grafts are the current gold standard for the reconstruction of such defects. However, due to increased patient morbidity and the need for a second operative site, other lines of treatment should be introduced. To find alternative unconventional therapies to manage such defects, bone tissue engineering using a combination of suitable bioactive factors, cells, and biocompatible scaffolds offers a promising new approach for bone regeneration. AIM To evaluate the healing capacity of platelet-rich fibrin (PRF) membranes seeded with allogeneic mesenchymal bone marrow-derived stem cells (BMSCs) on critically sized mandibular defects in a rat model. METHODS Sixty-three Sprague Dawley rats were subjected to bilateral bone defects of critical size in the mandibles created by a 5-mm diameter trephine bur. Ratssized mandibular bone defects in rats was better promoted by PRF membranes seeded with BMSCs than with PRF membranes alone. ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.BACKGROUND Keratoconus is a degenerative corneal disease characterised by aberrant cell behaviour and loss of matrix that can result in vision loss. Cells extracted from peripheral corneas can form stem cell-enriched spheres, which have shown the potential to repopulate the normal peripheral corneal stroma in vitro upon sphere implantation but have not been previously studied in keratoconic tissue. AIM To investigate the therapeutic potential of stem cell-enriched spheres formed from extracted peripheral human corneal cells when introduced to keratoconic tissue. METHODS Stem cell-enriched spheres were formed from extracts of normal cadaveric human peripheral corneal cells. These spheres were implanted into incisions created in full thickness and onto the surface of 10 ?m thin sections of keratoconic and normal stromal tissues in vitro. Tissue sections were used to maximise use of limited keratoconic tissue available for research. Living cells were stained with Calcein-AM and visualised with stereo and fluores ABCB5, ?Np63 and p63α were detectable by droplet digital PCR up to D14. Double immunolabelling revealed absence of ABCB5 staining in migrated cells but positive staining of alpha smooth muscle actin (myofibroblast marker) in some migrated cells. Droplet digital PCR showed similar expression patterns of differentiation markers but a reduction in stem cell markers between normal and keratoconic tissue with an increase in stromal cell markers and a reduction in epithelial cell markers, indicating an appropriate response to repopulating diseased tissue. CONCLUSION Cells from implanted stem cell-enriched spheres can repopulate a keratoconic corneal stromal surface in a directed manner and exhibit migratory stromal cell phenotypes. ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. https://www.selleckchem.com/products/ABT-888.html All rights reserved.Human induced pluripotent stem cells (hiPSCs) are invaluable resources for producing high-quality differentiated cells in unlimited quantities for both basic research and clinical use. They are particularly useful for studying human disease mechanisms in vitro by making it possible to circumvent the ethical issues of human embryonic stem cell research. However, significant limitations exist when using conventional flat culturing methods especially concerning cell expansion, differentiation efficiency, stability maintenance and multicellular 3D structure establishment, differentiation prediction. Embryoid bodies (EBs), the multicellular aggregates spontaneously generated from iPSCs in the suspension system, might help to address these issues. Due to the unique microenvironment and cell communication in EB structure that a 2D culture system cannot achieve, EBs have been widely applied in hiPSC-derived differentiation and show significant advantages especially in scaling up culturing, differentiation efficiency enhancement, ex vivo simulation, and organoid establishment. EBs can potentially also be used in early prediction of iPSC differentiation capability. To improve the stability and feasibility of EB-mediated differentiation and generate high quality EBs, critical factors including iPSC pluripotency maintenance, generation of uniform morphology using micro-pattern 3D culture systems, proper cellular density inoculation, and EB size control are discussed on the basis of both published data and our own laboratory experiences. Collectively, the production of a large quantity of homogeneous EBs with high quality is important for the stability and feasibility of many PSCs related studies. ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.Poor recovery of neuronal functions is one of the most common healthcare challenges for patients with different types of brain injuries and/or neurodegenerative diseases. Therapeutic interventions face two major challenges (1) How to generate neurons de novo to replenish the neuronal loss caused by injuries or neurodegeneration (restorative neurogenesis) and (2) How to prevent or limit the secondary tissue damage caused by long-term accumulation of glial cells, including microglia, at injury site (glial scar). In contrast to mammals, zebrafish have extensive regenerative capacity in numerous vital organs, including the brain, thus making them a valuable model to improve the existing therapeutic approaches for human brain repair. In response to injuries to the central nervous system (CNS), zebrafish have developed specific mechanisms to promote the recovery of the lost tissue architecture and functionality of the damaged CNS. These mechanisms include the activation of a restorative neurogenic program in a specific set of glial cells (ependymoglia) and the resolution of both the glial scar and inflammation, thus enabling proper neuronal specification and survival. In this review, we discuss the cellular and molecular mechanisms underlying the regenerative ability in the adult zebrafish brain and conclude with the potential applicability of these mechanisms in repair of the mammalian CNS. ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.